The present invention relates to a process for the preparation of liquid fuels and, more particularly, a process that allows a high sulfur fuel to be converted into energy by combustion with a substantial reduction in sulfur oxide emissions.
Low gravity, viscous hydrocarbons found in Canada, The Soviet Union, United States, China and Venezuela are normally liquid with viscosities ranging from 10,000 to 200,000 CP and API gravities of less than 12. These hydrocarbons are currently produced either by mechanical pumping, steam injection or by mining techniques. Wide-spread use of these materials as fuels is precluded for a number of reasons which include difficulty in production, transportation and handling of the material and, more importantly, unfavorable combustion characteristics including high sulfur oxide emissions and unburned solids. To date, there are two commercial processes practiced by power plants to reduce sulfur oxide emissions. The first process is furnace limestone injection wherein limestone injected into the furnace reacts with the sulfur oxides to form solid sulfate particles which are removed from the flue gas by conventional particulate control devices. The cost for burning a typical high sulfur fuel by the limestone injection method is between two to three dollars per barrel and the amount of sulfur oxides removed by the method is in the neighborhood of 50%. A more effective process for removing sulfur oxides from power plants comprises flue gas desulfurization wherein CaO+H.sub.2 O are mixed with the flue gases from the furnace. In this process 90% of the sulfur oxides are removed; however, the cost for burning a barrel of fuel using the process is between four and five Dollars per barrel. Because of the foregoing, the high sulfur content, viscous hydrocarbons have not been successfully used on a commercial basis as fuels due to the high costs associated with their burning.
Naturally it would be highly desirable to be able to use the hydrocarbons of the type set forth above as a a fuel.
Accordingly, it is a principal object of the present invention to provide a process for the production of a combustible fuel from bitumens and residual fuel oils.
It is a particular object of the present invention to produce a liquid fuel from natural bitumens and residual fuel oils by forming an oil in water emulsion.
It is a further object of the present invention to provide an oil in water emulsion for use as a liquid fuel having characteristics for optimizing the combustion process.
It is a still further object of the present invention to provide optimum burning conditions for the combustion of an oil in water emulsion of natural bitumens and residual fuels so as to obtain excellent combustion efficiency, low unburned particulate solids and low sulfur oxide emissions.
Further objects and advantages of the present invention will appear hereinbelow.